Answer:
T = 2 T₀
Explanation:
To answer this question let's write the expression for electrical conductivity
σ = n e2 τ / m*
The relationship with resistivity is
ρ = 1 /σ
Whereby the resistance
R = ρ L / A = 1 /σ L / A
We see that there is no explicit relationship between time and resistance, there is only a dependence on the life time (τ) that depends on the properties of the material, not on its diameter or length.
As also the average velocity or electron velocity of electrons is constant, the time to cross 2 mm in length is twice as long as the time to cross a mm in length
T = 2 T₀
The weight changes but the mass will stay the same.
//////Correct answer is C.///////
If you're listening to a sound that has a steady pitch, and suddenly the
pitch goes up, then you know that two things could have happened:
EITHER ...
-- The person or other source making the sound could have
raised the pitch of the sound being produced.
OR ...
-- The person or other source making the sound could have
started moving toward you.
OR ...
-- both.
Even if the pitch of the sound leaving the source doesn't change,
you would still hear it increase if the source starts moving toward
you. That's the so-called "Doppler effect".
Given : A ball of mass 40 g moving at a velocity of 4 m/s.
To find : Calculate the kinetic energy in joules ?
Solution :
The kinetic energy formula is given by,
where, v is the velocity v=4 m/s
m is the mass m=40 g
Convert g into kg,
Substitute the values,
Therefore, the kinetic energy is 0.32 Joules.
